Data Processing Method and Device for Battery Appearance Inspection

The present application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/KR2023/012875 filed Aug. 30, 2023, which claims priority from Korean Patent Application No.10-2022-0109760 filed in the Korean Intellectual Property Office on Aug. 31, 2022 and Korean Patent Application No.10-2023-0077509 filed in the Korean Intellectual Property Office on Jun. 16, 2023, the entire contents of which are incorporated herein by reference.

The present invention relates to a data processing apparatus and method for appearance inspection of batteries, and more particularly, to a data processing apparatus and method for appearance inspection of batteries with improved visual inspection efficiency.

Secondary batteries, capable of recharging and reuse, are manufactured as battery modules or packs by connecting multiple battery cells in series based on the required output capacity, serving as power sources for diverse applications. These batteries are used in small, high-tech electronic devices like smart phones, as well as a variety of fields including electric bicycles, electric vehicles, and energy storage systems (ESS).

Secondary batteries may be categorized into can-type batteries, where the electrode assembly is housed within a cylindrical metal can, and pouch-type batteries, where the electrode assembly is contained in a pouch-shaped case. Typically, cylindrical can-type batteries are recognized for their relatively large capacity and robust structural stability.

For a cylindrical battery, a manufacturing process may include an electrode preparation process, an electrode assembly manufacturing process, an electrode assembly packaging process, and a can assembly bonding process, and the manufactured cylindrical battery then undergoes a quality inspection process before its final shipment.

In the defect inspection process for the exterior of the battery, a two-dimensional image-based inspection method for the exterior of the battery is mainly used. Specifically, an operator checks the two-dimensional image of the outer surface of the battery displayed on the display device and determines whether there is a defect in a specific area to determine whether it is defective. Here, as it is judged whether the exterior of the battery is defective based on a plane image, which leads to a limit in terms of inspection accuracy and thus, the inspection time may be elongated.

As a technology to solve the above problems, an appropriate visual inspection technology is needed to more accurately and quickly determine whether the appearance of the battery is defective.

To obviate one or more problems of the related art, embodiments of the present disclosure provide a data processing apparatus for visual inspection of battery.

To obviate one or more problems of the related art, embodiments of the present disclosure also provide a data processing method performed by the data processing apparatus.

In order to achieve the objective of the present disclosure, a data processing apparatus for visual inspection of batteries may include at least one processor; and a memory having programmed thereon instructions that, when executed, are configured to cause the at least one processor to:

The instruction are further configured to cause the at least on processor to: receive a two-dimensional image of an outer lateral surface of the battery; and flatten the outer lateral surface of a cylindrical shape by applying a predefined distortion correction algorithm to the received two-dimensional image to generate the first image.

The instructions are further configured to cause the at least one processor to: calculate respective depth information for each plane coordinate of a plurality of plane coordinates of the first image using 3D shape data; and generate the second image by mapping the calculated respective depth information to each plane coordinate of the plurality of plane coordinates.

The second image may be a two-dimensional image, wherein the depth information of the outer surface of the battery is represented using one or more colors.

The instructions are further configured to cause the at least one processor to prompt a user to select one or more images from among the first image, the second image and third image and output the one or more images selected by a user.

The overlapping of the first image and the second image is visually represented using a preset transparency to generate a third image.

The at least one of the first image and the second image is output through the GUI based on a selection signal for a specific point in the first image or the second image, wherein the instructions are configured to cause the at least one processor to output a depth value for the specific point through the GUI.

The instructions are further configured to cause the at least one processor to generate and output a fourth image in which a tray containing a plurality of batteries is visualized; and in response to receiving a selection signal for one battery of the plurality of batteries in the fourth image, output the first image or the second image corresponding to the one battery of the plurality of batteries.

The instructions are further configured to cause the at least one processor to visualize one or more images of defective batteries among the plurality of batteries and one or more normal batteries among the plurality of batteries to generate and output a fourth image, wherein the images of the normal batteries are distinguishable from the images of the defective batteries.

The instructions may be further configured to cause the at least one processor to calculate an outer diameter value for the battery using the three-dimensional shape data; generate at least one of a fifth image that is a horizontal cross section of the battery visually representing the calculated outer diameter and a sixth image that is a vertical cross section of the battery visually representing the calculated outer diameter; and output at least one of the fifth image and the sixth image through the GUI.

The instructions may be configured to cause the at least one processor to calculate respective outer diameter value for each battery of a plurality of batteries included in the visual inspection, wherein the at least one of the fifth image and the sixth image is output through the GUI based on visualization of reference information, wherein the reference information includes one or more values among a minimum outer diameter value of the plurality of batteries, the maximum outer diameter value of the plurality of batteries, an average outer diameter value of the plurality of batteries and the upper specification limit and lower specification limit for the calculated outer diameter values, and wherein the reference information is output by overlapping the reference information with the at least one of the fifth image and the sixth image.

According to another embodiment of the present disclosure, a data processing method for visual inspection of batteries may include generating a first image representing a visually modified image of an outer surface of a battery using an originally captured image of the outer surface of the battery; generating a second image visually representing depth information of the outer surface of the battery by matching the first image with three-dimensional shape data associated with the outer surface of the battery; and outputting at least one of the first image and the second image through a predefined graphical user interface (GUI).

Generating the first image may include receiving a two-dimensional image of an outer lateral surface of the battery; and flattening the outer lateral surface of a cylindrical shape by applying a predefined distortion correction algorithm to the received two-dimensional image.

Generating the second image may include calculating respective depth information for each plane coordinate of a plurality of plane coordinates of the first image using 3D shape data; and generating the second image by mapping the calculated respective depth information to each plane coordinate of the plurality of plane coordinates.

The second image may be a two-dimensional image, and wherein the depth information on the outer surface of the battery is represented using one or more colors.

Outputting the at least one of the first image and the second image through the GUI may include prompting a user to select outputting one or more of the first image, the second image, and a third image in which the first image and the second image are overlapped.

The third image may be visualized based on the second image overlapped to the first image with a preset transparency.

Outputting one or more of the first image and the second image through the GUI may include in response to receiving a selection signal for a specific point in the first image or the second image, outputting a depth value for a specific point through the GUI.

Outputting the one or more of the first image and the second image through the GUI may include generating and outputting a fourth image in which a tray containing a plurality of batteries is visualized; and in response to receiving a selection signal for one battery of the plurality of batteries, in the fourth image, outputting the first image or the second image corresponding to the one battery of the plurality of batteries; and visualizing and outputting one or more images of defective batteries among the plurality of batteries and one or more images of normal batteries among the plurality of batteries, wherein the images of the normal batteries are distinguishable from the image of the defective batteries.

The method may further include calculating an outer diameter value for the battery using the three-dimensional shape data; generating at least one of a fifth image that is a horizontal cross section of the battery visually representing the calculated outer diameter and a sixth image that is a vertical cross section of the battery visually representing the calculated outer diameter; and outputting at least one of the fifth image and the sixth image through the GUI.

The one or more of the fifth image and the sixth image is output through the GUI based on visualization of reference information, wherein the reference information includes one or more values among of a minimum outer diameter value of the plurality of batteries, the maximum outer diameter value of the plurality of batteries, an average outer diameter value of the plurality of batteries and the upper specification outer diameter value limit and lower specification outer diameter value limit of the plurality of batteries, and outputting the reference information based on overlapping the reference information with the output image.

According to embodiments of the present disclosure, the accuracy and time efficiency of visual inspection of battery can be further improved.

The present invention may be modified in various forms and have various embodiments, and specific embodiments thereof are shown by way of example in the drawings and will be described in detail below. It should be understood, however, that there is no intent to limit the present invention to the specific embodiments, but on the contrary, the present invention is to cover all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention. Like reference numerals refer to like elements throughout the description of the figures.

It will be understood that, although the terms such as first, second, A, B, and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention. As used herein, the term “and/or” includes combinations of a plurality of associated listed items or any of the plurality of associated listed items.

It will be understood that when an element is referred to as being “coupled” or “connected” to another element, it can be directly coupled or connected to the other element or an intervening element may be present. In contrast, when an element is referred to as being “directly coupled” or “directly connected” to another element, there is no intervening element present.

The terms used herein is for the purpose of describing specific embodiments only and are not intended to limit the present invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “includes”, “including” and/or “having”, when used herein, specify the presence of stated features, integers, steps, operations, constitutional elements, components and/or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, constitutional elements, components, and/or combinations thereof.

Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meanings as commonly understood by one skilled in the art to which the present invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having meanings that are consistent with their meanings in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

is a block diagram of a visual inspection system according to embodiments of the present invention.

The visual inspection systemaccording to the present invention may be used in a process step of inspecting the appearance of the batteryfor defects. The visual inspection system may include a loading device for loading batteries, a transport device for transporting the loaded batteries to a specific location, a 2D camerathat photographs the outer surface of the battery at the specific location, and a 3D scannerthat generates three-dimensional shape data from the outer surface of the battery, and a visual inspection apparatusthat inspects appearance defects using the generated image.

The inspection object of the visual inspection system according to the present invention may be a cylindrical battery, but the scope of the present invention is not limited thereto.

The 2D camerais a device that produces a two-dimensional image by photographing the outer surface of the battery. Here, the 2D cameramay be arranged and configured at a specific location of an inspection facility to photograph one or more of the outer lateral surface, upper surface, and lower surface of the cylindrical battery.

The 3D scanneris a device that generates three-dimensional shape data about the outer surfaces of the battery. For example, the 3D scannermay correspond to an optical shape profile device that generates a three-dimensional data set of a cylindrical battery. Here, the 3D scannermay be configured to be placed at a specific location of the inspection facility to generate three-dimensional shape data for one or more of the outer lateral surface, the upper surface, and the lower surface of the cylindrical battery.

The visual inspection apparatusmay receive a two-dimensional captured image from the 2D cameraand three-dimensional shape data from the 3D scanner.

The visual inspection apparatusmay process the received two-dimensional captured image and three-dimensional shape data according to a predefined data processing process to generate one or more inspection images. Thereafter, the visual inspection apparatusmay output one or more generated inspection images through a predefined Graphical User Interface (GUI).

The display device may be included in the visual inspection apparatusor may be connected to the visual inspection apparatusthrough a network and output the generated inspection image through a predefined GUI. An operator may check the output inspection images to identify one or more of defects, defective items, and defect locations of the battery, and perform appearance inspection of the battery.

is an operational flowchart of a data processing method performed by a visual inspection apparatus according to embodiments of the present invention.

The visual inspection apparatus may generate a first image that visually represents the battery surface based on a captured image of the outer surface of the battery (S). Here, the first image may correspond to a two-dimensional image of a predefined size generated based on an image captured by a 2D camera.

In the embodiments, the visual inspection apparatus may receive a two-dimensional image of the outer lateral surface of the battery from a 2D camera, apply a predefined distortion correction algorithm to the received two-dimensional image, flatten the outer lateral surface, and produce a first image.

is a reference diagram for explaining a method of generating a first image according to embodiments of the present invention. Referring to, the visual inspection apparatus may receive a two-dimensional imageof the outer lateral surface of a cylindrical battery from a 2D camera. Thereafter, the visual inspection apparatus may apply a predefined distortion correction algorithm to the received two-dimensional imageto correct the cylindrical outer lateral surface to be planarized, thereby generating the first image. Here, the visual inspection apparatus may correct the distortion of the two-dimensional imagebased on the captured imageof a dummy can that has the same specifications as the battery to be inspected. For example, the visual inspection apparatus may correct the captured imageof the battery using a distortion correction algorithm that planarizes distorted grid pattern in the captured imageof a dummy can which has a grid pattern formed on the outer surface, thereby generating the first image.

In the embodiments, the visual inspection apparatus may apply a distortion correction algorithm to the captured imageto correct the cylindrical lateral outer surface to be plane, may convert the corrected two-dimensional image to a predefined size or extract a predefined area from the corrected two-dimensional image, and may generate the first image.